Photoflash lamp



April 2 1935 J. H. KURLANDER 1396,63

u PHOTOFLASH LAMP Filed Nov. 2B, 1933 ATTORNEY -erate at line voltage or able Switch.

mentioned, loosely disposed in vide a photoiiash lamp Patented Apr. 2,1935 l iran STATES rno'romsu LAMP `lohn H. Kurlander, Nutley,

Westinghouse Lamp Company,

Pennsylvania N. J., assgnor to a corporation of Application November 28, 1933;-Serial No. 700,042

9 Claims. (Cl. 6'1-31) This invention relates to a photoflash lamp and provides a rapid but intense source of illumination in the form oi aflash for photographic purposes. Lamps of this character are at present in wide useand are known as photoash lamps.`

Photoash lamps as shown and described in Reissue Patent 18,678 oi December 6, 1932, comprises a clear glass bulb filled with several sheets of aluminum toil which are crumpled about a lament or heater element coated with a quick ignition material or primer so that when"cur rent passes through the filament and heats the primer the foil is ignited and the combustion is accel rated by the presence of pure oxygen with which the bulb is filled. The bulb is provided with the usual screw threaded lamp type oi base and lead wires are provided nected to the terminals of the heater element. These photoash lamps are made either to opby means oi a battery in a holder having a socket for the lamp and asuit- When a lamp is ilashed, hot particles of melted foil are projected to the wall oi the bulb which often cause cracking-or breaking. The inside surfaces of the walls of the bulbs are, therefore, provided with an invisible layer of lacquer or cellulose to take the impact and dissipate the heat 'from the hot'particles preventing breaks.

The foil in lamps now being useds, as above the bulb and when ashed the degree of illumination rises from zero in a quickly rising curve to what may be called a sharp peak and then tapers oil to zero.

\ When taking a photograph with a photoilash lamp it is, obviously, desirable to operate the shutter of the camera at the high intensity point of the light. There is, however, a starting lag which must be considered and the duration of the ilash is so short,usually about-.015 to-.026 of a second including the lag, that means for operating a shutter at the instant the ash occurs, or

preferably at the peak of the flash, requires delicate and accurate synchronizing mechanism. This condition makes it diillcult to obtain the best results and it is especially necessary to provide photoash lamps which will operate exactly alike. This is also 'a difcult condition to contend with from a manufacturing standpoint, particularly since` photoiiash bulbs .are made to sell at a relatively low price. and must be produced at a high rateof speed. y

It is .an object oi the present invention to prowhich will operate to give a relatively high degree of light ici' a vrelatively long period as compared with lamps as heretofore employed. Y Another object` of the in'ention photoashlamp so constructeda to control the combustion of the light-giving material.

having ends con-- is to provide a Another object of the invention is to provide a photofiash lamp containing combustible lightgiving material so arranged longed concentrated flash.

Other objects and advantages of the invention will be more clearly'understood b y reference to as to produce a pro-' the following description together with the accompanying drawing in which Fig. 1 Vshows a photoflash lamp having the combustible materialarranged and supported in accordance with the present invention;

Fig. 2 is` a fragmentary enlarged view .of the lamp showingthe press and a supporting disk;

Fig. 3.is a view taken online III-III in Fig. l; and 1 Fig. 4 is a modified with two compartments to contrpl the combustion of the light giving material.

A photoash lamp lconstructed in accordance' with the present l0 having the usual base l I and a press l2. Ex-

nvention may comprise a bulb tending upwardly from the press are conductive supports |2'- and I3 connected to the4 terminals of a heater element or filament Il. The filament primer which in the present case is aluminum foill5. It has been found that when the foil is loose in the bulb it ashes instantaneously and in order to prolong the flash the selected embodiment of the invention provides means for extending the long length. 's

` Thistube or containermay preferablyvbe of a transparent material such ,as a sheet of transparentcellulose acetate of 'about three-quarters to one inch in diameter and it ispossible to enclose a container about six inches long within the construction showing a bulb A ashing period by arranging the foilin asinuous path.

bulb.v The foil may be crumpled and arranged in the container so that the volume of foil will be substantially uniform throughout the length of the container. It may not be necessary, however, to use a container of the greatest 'possible length and if desirable the-container may be in the form of a cup or cylinder about equal to the distance between the `press l2 and the top of the*r bulb. The container may be of a mesh material or may be a net of wide mesh whichvwill held the foil in a prearranged massto prolong the flash period. If the openings in the container are large it may not be necessary to make the container oi a material that will be destroyed in whichcase a wire cage may be used.

by the use of a thi which sheet may .sheet of cellulose, as shown, have 4perforations I1 to give quicker action. When the foil is dashed the conaccordance with easily handled for When a lamp is to be on the press I2, holes application to the bulbs. made a disk I8 is disposed f being .provided in the disk through which the duration of the Hash which tube. The tubeq or container also serves to prevent hot particles of foil from being thrown against the glass bulb and thus avoids the necessity of the inside coating oi' lacquer to formua protective layer as above mentioned. The containers for the foil as constructed in the present invention greatly facilitate the manufacture `,of the lamp since the may be termed cartridges and may be made up, handled, shaped and introduced into a bulb in a convenient and rapid manner which is noti possible when introducing loose sheets of foil as in lamps as heretofore made.

It will be understood- 2'I and 28 are connected to the aluminum foil /3I and lower compartment may contain pa of energy.

With the above construction the rate of combustion o1 tively long period o1' cases a bulb having ments .containing foil may be employed. The

degree of retardation of one flash a multiplicity of compartbehind the other may be controlled by the spacing between the individual llin partition or washer gs of foil. Forexample, the 10 30 may be crumpled to take up more space to delay the action or two partitions may be employed with a space therebetween.

pended claims.

What is claimed is:

1. A 'photoiiash lamp parent to light rays, material within said said material and combustible means for so sup porting thematerial combustion of said material 20 comprising a bulb transa quantity of combustible bulb, means for igniting the rate of 25 when ignited.

as to control 2. A photoash lamp comprising a transparent meansI surrounding said foil for controlling the 30 rate of combustion of 3. A photoas h-iamp comprising a transparent 'said foil.

means for confining `said material to a relatively 35 narrow path.

sa1d bulb, means for igniting igniting said foil. K

6. A photoash lamp comprising a transparent ted combustible tubular transparbulb, an elonga within said ent container bulb to provide a long dashing period, aluminum foil in said container and means for igniting 7. A photoiiash lamp parent to light rays`,'a of transparent dest bulb, a filling `oi al said foil. comprising a bulb transsinuous tubular container ructible material withinV said uminum foil in said container and' means for igniting said foil.

8. A photoiiash lamp comprising -a bulb transparent Vto light rays, destructible material within ysaid of transparent bulb, a lling ing said foil.

oi al andmeans disposed in a sinuous tubular container uml foil in said container said containerfor ignit- `9. A p hotoiiash lamp comprising aPbulbtransrent to light rays, a partition dividing the 

